Method of repositioning an injection port

ABSTRACT

A method of repositioning an injection port comprises positioning the injection port at a first location in a patient&#39;s body and extending fasteners of the injection port to substantially secure the injection port at the first location. The fasteners are then retracted to substantially unsecure the injection port from the first location in the patient&#39;s body. The injection port is then moved to a second location in the patient&#39;s body. The fasteners are then re-extended to substantially secure the injection port at the second location in the patient&#39;s body. The injection port includes a port body. The fasteners are integral with the port body. The fasteners may be selectively extended and retracted relative to the port body. For instance, the fasteners may be pivoted relative to the port body to transition between extended and retracted positions. The extension and retraction of fasteners may be provided through a port applier.

This application is a continuation of U.S. patent application Ser. No.11/166,625, filed Jun. 24, 2005, entitled “Implantable Medical Devicewith Reversible Attachment Mechanism and Method,” published as U.S. Pub.No. 2005/0283119, which is a continuation-in-part of U.S. patentapplication Ser. No. 10/741,875, filed Dec. 19, 2003, entitled“Subcutaneous Self Attaching Injection Port with Integral MoveableRetention Members,” published as U.S. Pub. No. 2004/0254537, whichclaims priority to U.S. Provisional Patent Application Ser. No.60/478,763, filed Jun. 16, 2003, entitled “Fluid Injection Port forAdjustable Gastric Band.” The disclosure of each of those three patentapplications is incorporated by reference herein.

This application also incorporates by reference the following UnitedStates patent applications, both of which were filed on Dec. 19, 2003:application Ser. No. 10/741,127, entitled “Subcutaneous Injection Portfor Applied Fasteners,” published as U.S. Pub. No. 2005/0131352; andapplication Ser. No. 10/741,868, entitled “Subcutaneous Self AttachingInjection Port with Integral Fasteners,” issued as U.S. Pat. No.7,374,557.

TECHNICAL FIELD

The present invention relates generally to medical implants and applierstherefor, and more particularly to an attachment mechanism for use witha variety of medical implants and appliers for attaching such medicalimplants to body tissue. The invention will be disclosed in connectionwith, but not limited to, surgically implantable injection ports and anapplier therefor.

BACKGROUND

Implantable medical devices are typically implanted in a patient toperform a therapeutic function for that patient. Non-limiting examplesof such devices include pace makers, vascular access ports, injectionports (such as used with gastric bands) and gastric pacing devices. Suchimplants need to be attached, typically subcutaneously, in anappropriate place in order to function properly. It is desirable thatthe procedure to implant such devices be quick, easy and efficient. Inmany instances it would be beneficial if the surgeon could remove orreposition the device quickly, easily and efficiently.

Injection ports are placed beneath the skin of a body for injectingfluids into the body, such as for infusing medication, blood draws, andmany other applications, including adjustable gastric bands. Since theearly 1980s, adjustable gastric bands have provided an effectivealternative to gastric bypass and other irreversible surgical weightloss treatments for the morbidly obese. The gastric band is wrappedaround an upper portion of the patient's stomach, forming a stoma thatrestricts food passing from an upper portion to a lower portion of thestomach. When the stoma is of the appropriate size, food held in theupper portion of the stomach provides a feeling of fullness thatdiscourages overeating. However, initial maladjustment or a change inthe stomach over time may lead to a stoma of an inappropriate size,warranting an adjustment of the gastric band. Otherwise, the patient maysuffer vomiting attacks and discomfort when the stoma is too small toreasonably pass food. At the other extreme, the stoma may be too largeand thus fail to slow food moving from the upper portion of the stomach,defeating the purpose altogether for the gastric band.

In addition to a latched position to set the outer diameter of thegastric band, adjustability of gastric bands is generally achieved withan inwardly directed inflatable balloon, similar to a blood pressurecuff, into which fluid, such as saline, is injected through a fluidinjection port to achieve a desired diameter. Since adjustable gastricbands may remain in the patient for long periods of time, the fluidinjection port is typically installed subcutaneously to avoid infection,for instance in front of the sternum. Adjusting the amount of fluid inthe adjustable gastric band is achieved by inserting a Huber needlethrough the skin into a silicon septum of the injection port. Once theneedle is removed, the septum seals against the hole by virtue ofcompressive load generated by the septum. A flexible conduitcommunicates between the injection port and the adjustable gastric band.

The present invention encompasses an attachment mechanism to secure anmedical implant device to body tissue quickly and easily. The attachmentmechanism may be reversible, allowing the implantable medical device tobe detached quickly and easily for repositioning or removal. Althoughstandard, commercially available instruments may be used to actuate theattachment mechanism, the present invention also encompasses an applierfor locating an implantable medical device in the desired location andquickly and easily actuating the attachment mechanism to secure theimplantable medical device.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention,and, together with the general description of the invention given above,and the detailed description of the embodiments given below, serve toexplain the principles of the present invention.

FIG. 1 is a perspective view of an injection port with an attachmentmechanism constructed in accordance with the present invention.

FIG. 2 is a top view of the injection port of FIG. 1.

FIG. 3 is a bottom view of the injection port of FIG. 1.

FIG. 4 is a cross sectional view of the injection port of FIG. 1 takenalong line 4-4 of FIG. 3.

FIG. 5 is an exploded perspective view of the injection port of FIG. 1.

FIG. 6 is perspective view of the bottom of the injection port of FIG.1, showing the attachment mechanism in the retracted position.

FIG. 7 is a perspective view of the bottom of the injection port of FIG.1, similar to FIG. 6, showing the attachment mechanism in theextended/fired position.

FIG. 8 is a side cutaway view in partial cross-section illustrating afastener of the attachment mechanism in the retracted position.

FIG. 9 is a side cutaway view in partial cross-section similar to FIG. 8illustrating a fastener of the attachment mechanism that is beingadvanced by the actuator ring toward the extended/fired position.

FIG. 10 is a side cutaway view in partial cross-section similar to FIG.8 illustrating a fastener of the attachment mechanism in theextended/fired position.

FIG. 11 is a side cutaway view in partial cross-section similar to FIG.8 illustrating a fastener of the attachment mechanism that is beingadvanced by the actuator ring toward the retracted position.

FIG. 12 is a top view of the injection port of FIG. 1, with the actuatorring omitted to illustrate the positions of the links when the fastenersare in the retracted position.

FIG. 13 is a top view of the injection port of FIG. 1, with the actuatorring omitted to illustrate the positions of the links when the fastenersare in the extended/fired position.

FIG. 14 is an enlarged, fragmentary top view of the visual positionindicator and actuator ring detent system of the attachment mechanism ofFIG. 1, in the retracted position.

FIG. 15 is an enlarged, fragmentary top view of the visual positionindicator and actuator ring detent system of the attachment mechanism ofFIG. 1 in the extended/fired position.

FIG. 16 is an enlarged, fragmentary, exploded perspective view of thefitting and locking connector of the injection port of FIG. 1.

FIG. 17 is an enlarged, fragmentary partial cross-section view of thelocking connector assembled to the fitting the septum retainer but notlocked in place.

FIG. 18 is an enlarged, fragmentary partial cross-section view similarto FIG. 17 showing the locking connector locked in place.

FIG. 19 is an enlarged perspective view of the safety cap.

FIG. 20 is a perspective view of an applier constructed to implant theinjection port of FIG. 1.

FIG. 21 is a exploded, perspective view of the applier of FIG. 20.

FIG. 22 is a side view of the applier of FIG. 20 with one of the twobody halves showing the internal components in the unapplied,non-actuated position.

FIG. 23 is a side view of the applier of FIG. 20 similar to FIG. 22,showing the internal components in the applied, actuated position.

FIG. 24 is an enlarged, fragmentary side view of the linear to rotarycam mechanism of the applier of FIG. 20.

FIG. 25 is an enlarged top perspective view of the locator of theapplier of FIG. 20.

FIG. 26 is an enlarged bottom perspective view of the locator and theport actuator of the applier of FIG. 20.

FIG. 27 is a partially cut away end view of the locator of the applierof FIG. 20.

FIG. 28 is an enlarged, cross sectional view of the injection port ofFIG. 1 retained by the locator of the applier of FIG. 20.

FIG. 29 is an enlarged, cross-sectional view of the injection port ofFIG. 1 disposed in the locator of the applier of FIG. 20 after theapplier has been actuated to rotate the applier actuator to the deployedposition.

FIG. 30 is a diagrammatic drawing showing an injection port connected toan adjustable gastric band wrapped around an upper part of a stomach.

Reference will now be made in detail to the present preferred embodimentof the invention, an example of which is illustrated in the accompanyingdrawings.

DETAILED DESCRIPTION

In the following description, like reference characters designate likeor corresponding parts throughout the several views. Also, in thefollowing description, it is to be understood that terms such as front,back, inside, outside, and the like are words of convenience and are notto be construed as limiting terms. Terminology used in this patent isnot meant to be limiting insofar as devices described herein, orportions thereof, may be attached or utilized in other orientations.Referring in more detail to the drawings, an embodiment of the inventionwill now be described.

Referring to FIGS. 1-5, there is shown an implantable medical device,more specifically an injection port, generally indicated at 2, whichembodies an attachment mechanism constructed in accordance with thepresent invention. Although the attachment mechanism is illustrated inthe figures as being embodied with injection port 2, the attachmentmechanism may be used with any implantable medical device for which itis suited, including by way of example only pace makers, vascular accessports, injection ports (such as used with gastric bands) and gastricpacing devices.

Injection port 2 includes septum retainer 4, septum 6 and port body 8.Injection port 2, with the integrally constructed attachment mechanism,also includes one or more fasteners 10, actuator 12 and a plurality oflink members 14.

As seen in FIG. 4, septum 6, which may be made of any biocompatiblematerial such as silicone, is disposed partially within internal cavity16 of septum retainer 4, adjacent annular flat 18. Septum retainer 4,port body 8, and actuator 12 may be made of any suitable biocompatiblematerial having sufficient stiffness and strength, such aspolyetheretherketon (known as PEEK). Fasteners 10 and link members 14may be made of any suitable biocompatible material, such as stainlesssteel.

Port body 8 includes annular rim 20, which engages the upper surface ofseptum 6 about an annular portion. Port body 8 is retained to septumretainer 4 by a plurality of pins 22 which are disposed throughrespective holes 24 formed in recesses 24 a in port body 8 and whichextend inwardly into respective recesses 26 formed about the bottomperiphery of septum retainer 4. Pins 22 may be made of any suitablebiocompatible material, such as stainless steel.

The uncompressed height of septum 6 is approximately 5 mm around theouter diameter and the uncompressed diameter is approximately 18 mm. Theexposed diameter for access to reservoir 20 is approximately 14 mm Thedistance between the lower surface of annular rim 20 and annular flat 18is approximately 4 mm, such that septum 6 is compressed approximately20% to be adequately self healing to maintain a fluid tight system underpressure and still allow a low profile.

Plate 28 is disposed in recess 16 a formed in the bottom of septumretainer 4, underlying septum 6 and fluid chamber or reservoir 30. Asseen in FIG. 4, plate 28 does not contact sidewall 16 b. In theembodiment depicted, plate 28 is metallic, such as stainless steel. Whena needle is inserted through septum 6 to introduce or withdraw fluidfrom fluid chamber 30, such as in order to adjust the size of anadjustable gastric band, metallic plate 28 will protect septum retainer4 from puncture and provide tactile feedback to the surgeon through theneedle indicating that the needle has bottomed in reservoir 30. Plate 28may be secured to septum retainer 4 in any suitable manner. In theembodiment depicted, plate 28 is held in place by retaining lip 4 aextending over the periphery of plate 28 as best seen in FIGS. 4, 28 and29. Initially, retaining lip 4 a extends upwardly as an annular lip,providing clearance for insertion of plate 28 into the recess at thebottom of septum retainer 4, and retaining lip 4 a is then rolled orotherwise deformed to overlie at least a portion of the periphery ofplate 28 thereby retaining plate 28. In the embodiment depicted thediameter of recess 16 a is smaller than the diameter of sidewall 16 b,providing room to form the annular lip and to deform it into retaininglip 4 a. Plate 28 could be insert molded, with retaining lip 4 a moldedas illustrated.

Septum retainer 4 includes passageway 32, in fluid communication withfluid chamber 30, which is defined by fitting 34 extending from theperiphery adjacent the bottom of retainer 4. Tube 36, which in theembodiment depicted, leads to an adjustable gastric band (not shown), isconnected to fitting 34, being compressingly urged against annular rib38 by connector 40, which is disposed about tube 36 and secured to portbody 8 as described below. Sleeve 42 is disposed about tube 36, securedto connector 40 by annular ribs 44. Sleeve 42 relieves strain on tube36, preventing tube 36 from kinking when loaded laterally.

Actuator 12 is secured to port body 8. Although in the embodimentdepicted actuator 12 is illustrated as an annular ring rotatablysupported by port body 8, actuator 12 may be any suitable configurationand supported in any suitable manner to permit actuator 12 to functionto move fasteners 10 between and including deployed and undeployedpositions. As seen in FIG. 5, port body 8 includes a plurality ofdownwardly and outwardly extending tabs 46. In the embodiment depicted,there are four equally spaced tabs 46. Actuator 12 includes an equalnumber of corresponding recesses 48, each having arcuate bottom 50. Toassemble actuator 12 to port body 8, recesses 48 are aligned with tabs46, and pushed down, temporarily deflecting tabs 46 inwardly until tabs46 reach recesses 48 and move outwardly to dispose lower edges 46 a inrecesses 48 such that actuator is retained thereby. The lengths of tabs46 and depth of recesses 48 allow some axial end play between actuator12 and port body 8, as will be described below.

Actuator 12 may rotate generally about the central axis of port body 8.In the embodiment depicted, actuator 12 may rotate through an angle ofabout 40 degrees, although any suitable angle may be used. In theembodiment depicted, when actuator 12 is rotated in the deployingdirection, causing fasteners 10 to move to the deployed position,rotation of actuator 12 beyond the fully deployed position is limited byend 48 c contacting tab 46.

A detent system is formed by a pair of spaced apart raised detent ribs48 a, 48 b extending inwardly from the wall of each recess 48, and acorresponding raised rib 46 b extending outwardly from tab 46. Thedetent system assists in preventing actuator 12 from rotation andfasteners 10 from moving out of fully retracted or fully extended firedstates under vibration or incidental loads, as described below.

Actuator 12 includes a plurality of spaced apart openings or slots 54,which may be engaged by any suitable instrument to transmit thenecessary torque to actuator 12 to extend fasteners 10 to the actuatedposition. Slots 54 are configured to be engaged by commerciallyavailable instruments, rectangular in the embodiment depicted, or by thededicated applier described below. Port body 8 includes a plurality ofrecesses 56 disposed about its lower periphery which are configured tocooperate with the dedicated applier as described below.

Referring also to FIGS. 6 and 7, septum retainer 4 includes a pluralityof locating tabs 58 extending outwardly from adjacent the bottomperiphery of septum retainer 4. Locating tab 58 a may be integral withfitting 34. Tabs 58 and 58 a are located in respective complementarilyshaped recesses 60 formed in the inner surface of port body 8, aligningseptum retainer 4 properly with port body 8.

FIG. 6 illustrates fasteners 10 in the retracted position. As can beseen, fasteners 10 are disposed in respective recesses or slots 60formed in port body 8. FIG. 7 illustrates fasteners 10 in the extended,or fired, position, extending from slots 60. Rotation of actuator 12moves fasteners 10 from the retracted position to the extended position.

FIGS. 8-11 are a series of figures illustrating the operation ofactuator 12 and one of the plurality of fasteners 10, it beingunderstood that the operation on one of fasteners 10 may be the same asfor all fasteners 10, which may, in one embodiment, be moved from adeployed position to an undeployed position simultaneously. FIG. 8illustrates fastener 10 in a fully retracted state, the undeployedposition, disposed completely within slot 62 such that sharp tip 64 isnot exposed. This prevents tip 64 from accidentally sticking the surgeonor penetrating any object. Actuator 12 is illustrated rotated counterclockwise as far as permitted by recesses 48 and tabs 46. In thisposition, ribs 46 b are disposed clockwise of ribs 48 b, as seen in FIG.14. First ends 14 a of link members 14 are rotatably carried by actuator12, spaced apart at positions corresponding to the positions offasteners 10. Second ends 14 b are disposed within openings 66 offasteners 10.

To actuate the attachment mechanism, integral actuator 12 is rotated ina deploying direction, which in one embodiment as depicted is clockwise(any suitable direction configured to actuate the attachment mechanismmay be used), and rib 46 b passes rib 48 b, which may produce an audiblesignal in addition to a tactile signal to the surgeon. Second end 14 bof link member 14 is free to move within slot 66 during actuation, asthe force that rotates fastener 10 into the extended position istransmitted to fastener 10 through the interaction between cam surface68 of fastener 10 and actuating cam surface 70 of actuator 12. Asactuator 12 rotates clockwise, actuating cam surface 70 engages andpushes against cam surface 68, rotating fastener 10 about pivot pin 22.The majority of the force from actuating cam surface 70 actstangentially on cam surface 68, off center relative to pivot pin 22,causing fastener 10 to rotate. During actuation, end 14 b of link member14 remains free to move within slot 66, applying no driving force torotate fastener 10.

In FIG. 9, fastener 10 is rotated about half way though its range ofrotation, about 90 degrees as a result of the clockwise rotation ofactuator 12. As actuator 12 is rotated clockwise, the force betweenactuator cam surface 70 and cam surface 68 causes actuator 12 to moveupward slightly as allowed by the tolerancing of the components. Asactuator 12 is rotated further clockwise from the position shown in FIG.9, actuator cam surface 70 continues to engage and push against camsurface 68, rotating fastener 10 further counterclockwise.

In FIG. 10, actuator 12 is rotated clockwise to its fullest extent, withrib 46 b having been urged past detent rib 48 a (see FIG. 15). In thisposition, fastener 10 has rotated to its fullest extent, almost 180degrees in the embodiment illustrated, with tip 64 disposed withinrecess 62. In this position, actuator cam surface 70 is over center, andactuator 12 is resistant to being back driven by an undeploying forceimparted to fastener 10 as cam surface 68 acts against actuator camsurface 70 in a direction that tends to push actuator 12 up instead ofrotating actuator 12. The distal end portion of fastener 10 isconfigured essentially as a beam, depicted as having a generallyrectangular cross section along its length, tapering to sharp tip 64.With fastener 10 extending approximately 180 degrees in the fullyextended state, the deployed position, forces which might act onfasteners 10 tend to act through the pivot axis defined by pivot pin 22,instead of rotating fasteners 10. It is noted that although pin 22 isillustrated as being a separate piece from fastener 10, the two may beintegral or even of unitary construction.

If it is desirable to retract fasteners 10, such as to remove orreposition the implanted device, actuator 12 may be rotated in anundeploying direction, counterclockwise in one embodiment depicted.Starting with the position of actuator 12 shown in FIG. 10, actuator 12may be rotated counterclockwise, with actuator cam surface 70 slidingagainst cam surface 68, without rotating fastener 10. In the embodimentdepicted, continued counterclockwise rotation of actuator 12 moves camsurface 70 out of contact with cam surface 68, with no substantialrotating force being exerted on fastener 10 until second end 14 b oflink member reaches a location in slot 66, such as at one end of slot66, at which link member 14 begins pulling against slot 66 causingfastener 10 to rotate and begin to retract.

As seen in FIG. 11, actuator 12 has been advanced counterclockwisecompared to the position shown in FIG. 10, and fastener 10 is rotatedapproximately halfway through its range. As can be seen by comparingFIG. 9 to FIG. 11, actuator 12 is in different positions with fastener10 in the same position, in dependence upon whether the attachmentmechanism is being actuated or deactuated (retracted). This results fromthe lost motion that results when link member 14 is pulling on slot 66in comparison to actuator cam surface 70 pushing directly on cam surface68. To retract fasteners 10 fully, actuator 12 is rotated until detentrib 46 b snaps past detent rib 48 b.

Referring to FIG. 8, when fasteners 10 reach the fully undeployedposition tip 64 may be disposed fully in slot or recess 62. Furtherundeploying rotation of actuator 12 is prevented by link member 14 whichis prevented from further movement by fastener 10.

Referring to FIGS. 2 and 3, actuator 12 includes openings 52 a formedtherethrough, which align with corresponding openings 52 b formed inport body 8 when actuator is in the undeployed position. Openings 52 aand 52 b may be used by the surgeon to suture injection port 2 if theintegral attachment mechanism is not used.

Referring to FIGS. 12 and 13, the attachment mechanism is shown withoutactuator 12. Link members 14 are shown in their actual positions whenfirst ends 14 a are supported by actuator 12, in the deployed and in theundeployed states.

Referring to FIGS. 14 and 15, there is illustrated a top view of thevisual position indicator and a portion of the actuator ring detentsystem of the attachment mechanism as embodied in injection port 2. InFIG. 14, the attachment mechanism is in the retracted, undeployed stateor position. In this position, detent rib 46 b is clockwise of detentrib 48 b, and thus in the undeployed detent position. In FIG. 15, theattachment mechanism is in the actuated or deployed position. In thisposition, detent rib 46 b is counterclockwise of detent rib 48 b, andthus in the deployed detent position.

FIGS. 14 and 15 illustrate a visual indicator of the state of theattachment mechanism. As seen in FIG. 14, indicia may be utilized, suchas an unlocked lock icon 72 and a locked lock icon 74 molded integralwith actuator ring 12. Any suitable graphic indicator may be used, andmay be printed on or otherwise applied in a suitable manner. Port body 8may include indicator 76 to provide a reference point for the movableindicia. Arrow 78 may be included to indicate the bidirectional motionof actuator 12.

FIGS. 16-18 illustrate the locking connection between connector 40 andport body 8. FIG. 16 is an exploded perspective view showing fitting 34partially surrounded by extension 78. FIG. 17 shows extension 78 incross-section, with connector 40 generally disposed about fitting 34 andtube 36 aligned in circumferential slot 78 c of extension 78. Connector40 includes a pair of tabs 40 a, 40 b, extending outwardly therefrom. Toassemble, connector 40 is guided along tube 36 and fitting 34, with tabs40 a and 40 b aligned with openings 78 a and 78 b of extension 78. Withtabs 40 a and 40 b aligned with circumferential slot 78 c, connector 40is rotated to lock it in place. During rotation, detent edge 78 dcreates interference opposing the rotation of tab 40 a, but isdimensioned to allow tab 40 a to be rotated past, to the locked positionseen in FIG. 18.

FIG. 19 illustrates safety cap 80 which may be removably secured to thebottom of injection port 2 to cover fasteners 10 to protect users fromaccidental exposure to sharp tips 64 while handling injection port 2.Safety cap 80 includes body 82 with annular rim 84 and raised center 86defining annular recess 88. Safety cap 80 may be oriented and retainedto injection port through any suitable configuration. As depicted, body82 includes a plurality of arcuate retention tabs 90 extending upwardlyfrom raised center 86. Arcuate retention tabs 90 are shapedcomplementarily to corresponding arcuate slots 92, best seen in FIGS. 3,6 and 7, and may have ribs as shown. Safety cap 80 is secured toinjection port 2 by inserting arcuate retention tabs 90 into arcuateslots 92, which are sized to retain tabs 90. Fasteners 10 are thusaligned with annular recess 88, which is sized to allow fasteners 10 tobe extended without contacting safety cap 80. As depicted, since arcuateretention tabs 90 and arcuate slots 92 are respectively the same sizeand equally spaced, safety cap 80 is not indexed to a particularposition, and may be secured to injection port 2 in four differentpositions. Safety cap 80 includes pull tab 94 with raised a plurality ofribs 96 to provide a better gripping surface. Although pull tab 94 maybe oriented in any suitable orientation, in the embodiment, the relativeposition between pull tab 94 and arcuate retention tabs 90 locates pulltab at 45 degrees to the direction of connector 40. Tabs 90 and slots 92may be of any suitable shape.

As mentioned previously, the attachment mechanism may be actuated byengaging slots 54 with commercially available instruments or by adedicated applier. FIG. 20 illustrates applier, generally indicated at100, which is configured to position, actuate, deactuate, remove orreposition injection port 2. It is noted that the practice of aspects ofthe present invention as applied to an applier is not limited to thespecific applier embodiment depicted herein.

As shown in FIG. 20, applier 100 includes body 102, locator 104,actuator 106 and safety switch 108. As will be described below,injection port 2 may be assembled to locator 104, with extension 78 andtab 96 disposed in alignment slots 110 and 112. Locator 104 is angledrelative to body 102, allowing for easier and better visualization ofinjection port 2 during implantation. In the embodiment depicted, theangle is 20 degrees and the shaft portion of body 102 is 10 cm.

Referring to FIG. 21, body 102 includes first and second halves 102 aand 102 b assembled to each other to contain the internal components.Except for locating pins 202, pivot pins 114 and ship laps, body halves102 a and 102 b are substantially similar to each other. Locating pins202, illustrated as extending from body half 102 a, fit into respectivecomplementarily shaped openings (not illustrated) on body half 102 b.The engagement of the plurality of locating pins 202 in the openings issufficient to hold body halves 102 a and 102 b together. Pins 202 mayalternatively extend from body half 102 b with the openings carried bybody half 102 a. Any suitable configuration may be used to assemble andsecure body halves 102 a and 102 b together.

Actuator 106 includes first and second halves 106 a and 106 b. Locatingpins 204, illustrated as extending from actuator half 106 a, fit intorespective complementarily shaped openings (not illustrated) on actuatorhalf 106 b. Pins 204 may alternatively extend from actuator half 106 bwith the openings carried by actuator half 106 a. Any suitableconfiguration may be used to assemble and secure actuator halves 106 aand 106 b together. Body half 102 b includes pivot pin 114 b whichrotatably supports actuator 106 at one end, extending through pivotholes 116 a and 116 b into opening 114 a. Body half 102 a includes pivotpin 118 b (see FIG. 22) which rotatably supports safety switch 108. Bodyhalves 102 a and 102 b, locator 104, actuator halves 106 a and 106 b,and safety switch 108 may be made of any biocompatible material such aspolycarbonate.

Referring to FIGS. 21-24, applier 100 includes cam 120, drive shaft 122with flexible shaft 124, drive shaft pin 126, cam return spring 128,safety biasing spring 130, and actuator 132. Actuator 132 is configuredto effect the deployment or undeployment of the attachment mechanism ofthe medical implant. Cam 120 includes shaft 134 and cam collar 136. Theupper end of shaft 134 has a “T” configuration terminating in crossmember 138. Cam collar 136 defines a hollow interior and a pair ofspaced apart, complementarily shaped cam tracks 140 a and 140 b formedon opposite sides of cam collar 136. Upper end 122 a of drive shaft 122is disposed partially within the hollow interior defined by cam collar136, captured therein by drive shaft pin 126. Drive shaft pin 126 issized such that each end is located within a respective cam track 140 a,140 b. The length of the hollow interior allows upper end 122 a toreciprocate therein, with cam tracks 140 a and 140 b imparting rotationto drive shaft 122 through drive shaft pin 126 during reciprocation. Cam120, drive shaft 122 and actuator 132 may be made of any suitablematerial having sufficient stiffness and strength. In the embodimentdepicted, cam 120 and actuator 132 are made of a liquid crystal polymersuch as Vectra™ LCP, and drive shaft 122 is made of a PPE+PS such asNoryl™. Drive shaft pin 126 and cam return spring 128 may be made of anysuitable material, such as stainless steel.

Cam 120 is retained between body portions 102 a and 102 b, and in oneembodiment, such as that depicted can reciprocate. Cam collar 136 hasspaced apart, generally flat outer surfaces 142 a and 142 b tracksthrough which 140 a and 140 b are formed. These surfaces 140 a and 140 bare disposed between guide walls 144 a and 144 b formed in body portions102 a and 102 b. Cam collar 136 also includes oppositely facing channels146 a and 146 b (see FIG. 23), which are guided for axial reciprocationby guides 148 a and 148 b (not illustrated) formed in body portions 102a and 102 b, respectively. The upper end of shaft 134 and cross member138 are disposed sandwiched between actuator halves 106 a and 106 b.Each actuator half 106 a, 106 b, includes a cam track 150 defined by apair of spaced apart walls 150 a and 150 b extending from the interiorsurfaces of actuator halves 106 a and 106 b. Cam track 150 is configuredto receive and guide cross member 138 as actuator 106 is rotated aboutpin 114, forcing cam 120 to advance linearly downwardly into body 102.

Drive shaft 122 includes annular collar 152 which is received in slots154 a and 154 b (not illustrated) formed in body halves 102 a and 102 b,respectively. Slots 154 a and 154 b rotatably support drive shaft 122.Drive shaft 122 and cam 120 are generally aligned and collinear witheach other, defining the axis of the shaft portion of body 102. As cam120 is advanced downwardly, drive shaft pin 126 follows cam tracks 140 aand 140 b, causing drive shaft 122 to rotate, thus converting linearmotion to rotary motion. Cam return spring 128 provides a nominal returnforce against cam collar 136.

Flexible shaft 124 is supported by a plurality of ribs 156, formed ineach body half 102 a, 102 b, which support the bend in flexible shaft124 that permits the rotary motion to be transferred to actuator 132which is disposed at an angle relative to the shaft of body 102.Flexible shaft 124 may be made of any suitable biocompatible material,such as stainless steel. In an embodiment depicted, flexible shaft 124has a stranded construction, with a center core having multiple layersof wire wrapped thereabout. Ends 124 a and 124 b of flexible shaft 124may be attached to end 122 b and actuator 132, respectively, in anysuitable manner which sufficiently limits rotational end play to preventor minimize lost rotational motion. In an embodiment depicted, end 124 awas overmolded into end 122 b, and end 124 b was press fit into actuator132. Alternatively, end 124 a could be press fit into end 122 b, and end124 b overmolded into actuator 132, both could be press fit, or bothcould be overmolded (with a corresponding change to the configuration oflocator 104 to allow assembly.

Referring to FIGS. 21-25, actuator 132 includes disc shaped member 158and shaft 160 extending upwardly therefrom. The upper end of shaft 160includes a pair of outwardly extending tabs 162 a and 162 b. Locator 104includes hub 164 defining bore 166 therethrough. Bore 166 is shaped toreceive and rotatably support shaft 160, and includes two outwardlyextending arcuate recesses 168 a and 168 b configured to provideassembly clearance for tabs 162 a and 162 b, allowing hub 164 to beinserted into bore 166. The lengths of shaft 160 and hub 164 are sizedsuch that tabs 162 a and 162 b are located above upper surface 164 a ofhub 164, allowing rotation of actuator 132 while retaining it axiallyrelative to hub 164. Stops 170 and 170 b extend upwardly from uppersurface 164 a, limiting the rotation of actuator 132. Bore 166 defines acentral axis of locator 104 about which actuator 132 is rotated. Thecentral axis of locator 104 is disposed at an angle to the axis of theshaft portion of body 102, as previously mentioned.

Hub 164 includes a pair of oppositely extending tabs 172 a and 172 bwhich retain port actuator 104 to body 102 and prevent rotation. Bodyhalves 102 a and 102 b include respective recesses 174 a (see FIG. 21)and 174 b (not illustrated) shaped complementarily to tabs 172 a and 172b.

Referring also to FIGS. 26 and 27, disc shaped member 158 of actuator132 is seen disposed within locator 104. Actuator 132 includes a pair ofspaced apart posts 176 a and 176 b, extending from adjacent periphery158 a of member 158. Posts 176 a and 176 b are shaped complementarilywith openings 54. In the embodiment depicted, the distal ends of posts176 a and 167 b are tapered to assist in guiding posts 176 a and 176 binto openings 54. Any suitable configuration may be utilized to createreleasable contact between actuator 132 and actuator 12 capable ofactuating actuator 12.

Disc shaped member 158 also includes a pair of spaced apart cams 178 aand 178 b which extend outwardly and upwardly from periphery 158 a ofmember 158. FIG. 27 illustrates cam 178 a at a cross-section taken nearthe bottom surface of member 158. Cams 178 a and 178 b include ramps 180a and 180 b which start at periphery 158 a and lead out to surfaces 182a and 182 b, respectively. Each surface 182 a, 182 b is arcuate, shownin the embodiment depicted as generally having a constant radius.

In the embodiment depicted, locator 104 includes a pair of spaced apartcantilever arms 184 a and 184 b, each having rib 186 a and 186 b,respectively. For clarity, FIG. 27 illustrates arm 184 a incross-section taken through rib 186 a, at the same level as for cam 178a. At their distal ends, arms 184 a and 184 b include respectiveinwardly extending flanges 188 a and 188 b. Flanges 188 a and 188 b areshaped complementarily to recesses 56 on port body 8, configured toengage ledges 56 a when injection port 2 is retained by locator 104.

In the embodiment depicted, in the non-actuated state, posts 176 a and176 b are generally aligned with arms 184 a and 184 b, respectively,although posts 176 a and 176 b may be at any position that correspondsto position of the actuating feature of actuator 12, which in theembodiment depicted is openings 54. As actuator 106 is depressed,actuator 132 rotates (counterclockwise in the embodiment depicted whenviewed from the bottom), advancing cams 178 a and 178 b such that ramps180 a and 180 b contact ribs 186 a and 186 b, respectively, deflectingarms 184 a and 184 b outwardly. When surfaces 182 a and 182 b engageribs 186 a and 186 b, arms 184 a and 184 b are deflected a distancesufficient to move flanges 188 a and 188 b to a position where they nolonger extend into recesses 56 or contact ledges 56 a, thus releasinginjection port 2 from locator 104.

FIG. 28 illustrates injection port 2 disposed in and retained by locator104, with extension housing 78 and tab 96 disposed in slots 110 and 112,respectively (see FIG. 20, not seen in FIG. 28). As depicted, posts 176a and 176 b extend into openings 54 of actuator 12, and flanges 188 aand 188 b extending into recesses 56 proximal ledges 56 a. Safety cap 80is connected to injection port 12 when injection port 12 is insertedinto locator 104, covering fasteners 10 (not seen in FIG. 28).

Referring also to FIGS. 20 and 22, to insert injection port 2 intolocator 104, actuator 106 is oriented in the undeployed position so thatactuator 132 is in the undeployed position. Actuator 12 is oriented inthe undeployed position, and inserted into locator 104, with extensionhousing 78 and tab 96 disposed in slots 110 and 112, respectively.

Actuator 106 may, as illustrated in FIG. 20, include a visual indicatorto indicate whether actuator 106 is fully in the undeployed state, suchas unlocked lock icon 190, and indicia to indicate whether actuator 106is in the deployed state, such as locked lock icon 192. Such visualindication may be include by any suitable manner, such as by moldingintegral with actuator 106, applying as a adhesive film or such, orprinting directly on actuator 106. With the indicator illustrated,unlocked lock icon 190 is visible adjacent the upper edge of body 102,although other configurations of indication may be utilized, such as awindow or such formed in body 102 to reveal the indicia.

To use, locator 104 and a portion of 102, if necessary, is insertedthrough an incision by the surgeon and located in the desired positionadjacent the body tissue to which the medical implant (which in theembodiment depicted is an injection port 2) is to be attached. The anglebetween locator 104 and body 102 allows the surgeon to visualize thesite directly. With injection port 2 in position, the one or morefasteners 10 are moved from the undeployed position to the deployedposition in an annular path to engage the tissue. Fasteners 10 allowinjection port 2 to be secured to the tissue with a retention strengthequal to or greater than when secured with sutures. Safety switch 108 isrotated about pivot pin 118, withdrawing lockout tab 194 from loweropening 196, allowing actuator 106 to be rotated about pivot pin 114.This action causes cam track 150 to move cross member 138 downward,causing cam collar 136 to rotate drive shaft 122, thereby rotatingactuator 132 relative to locator 104.

Rotation of actuator 132 actuates actuator 12 by rotating it. Theengagement between extension 78 and tab 96 and slots 110 and 112,respectively, prevent port body 8 from rotating, allowing relativemotion between actuator 12 and port body 8.

Once actuator 106 reaches the deployed position, lockout tab 194 isurged into upper opening 198, retaining actuator 106 in the deployedposition. In the embodiment depicted, spring 130 biases lockout tab 194sufficiently to produce sound as lockout tab 194 snaps into upperopening 198, providing an audible signal that actuator 106, andtherefore actuator 12 and fasteners 10 are deployed fully. Asillustrated in FIG. 29, with actuator 106 in the deployed position,actuator 12 has been rotated and fasteners 10 are in the deployedposition having penetrated the body tissue, such as the rectus sheath.Cams 178 a and 178 b have been rotated to a position where surfaces 182a and 182 b are adjacent ribs 186 a and 186 b, with arms 184 a and 184 bdeflected outwardly such that flanges 188 a and 188 b are not disposedin recesses 56 and not engaging ledges 56 a. With injection port 2secured to the body tissue, and released from locator 104, the surgeonmay withdraw locator 104, leaving injection port 2 in place. If a visualindicator of the state of the attachment mechanism is included with theimplant, the surgeon can tell whether the attachment mechanism is fullydeployed.

The attachment mechanism embodied in injection port 2 is configured tobe reversible so that the medical implant, injection port 2, may bemoved, such as to reposition it or remove it from the patient. To do so,with actuator 106 in the deployed position, locator 104 is placed overinjection port 2, locating extension 78 and tab 96 in slots 110 and 112so that posts 176 a and 176 b are engaged with recesses 54. Safetyswitch 108 is rotated to withdraw lockout tab 194 from upper opening198, while the surgeon pulls up on extension 200 of actuator 106.Although cam return spring 128 urges cam collar 136 upwardly, extension200 allows an additional return force to be applied. As cross member 138is pulled up by cam track 150, actuator 132 rotates actuator 12, movingfasteners 10 from the deployed position to the undeployed positionsimultaneously, while cams 178 a and 178 b disengage from ribs 186 a and186 b, allowing flanges 188 a and 188 b to engage recess 56 and ledge 56a so as to retain injection port 2 in locator 104. When actuator 106 hasbeen moved to the undeployed position, lockout tab 194 snaps into loweropening 196, generating an audible signal that actuator 106 isundeployed fully, and injection port 2 is detached from the body tissueand may be relocated or removed.

In FIG. 30, adjustable gastric band 210 is shown wrapped around an upperportion of stomach 212, kept in place by attaching the two ends togetherand extending portion 214 of the stomach 212 over adjustable gastricband 210 by suturing portion 214 to the stomach. One end of flexibleconduit 216 is in fluid communication with the internal cavity of theballoon (not shown), with the other end being in fluid communicationwith an internal cavity of injection port 218. At the time adjustablegastric band 210 is implanted around a portion of the stomach, remoteinjection port 218 is also implanted at a suitable location, usuallywithin the rectus sheaths, for transcutaneous access via a Huber needle.

In summary, numerous benefits have been described which result fromemploying the concepts of the invention. The foregoing description ofone or more embodiments of the invention has been presented for purposesof illustration and description. It is not intended to be exhaustive orto limit the invention to the precise form disclosed. Modifications orvariations are possible in light of the above teachings. The one or moreembodiments were chosen and described in order to illustrate theprinciples of the invention and its practical application to therebyenable one of ordinary skill in the art to utilize the invention invarious embodiments and with various modifications as are suited to theparticular use contemplated. It is intended that the scope of theinvention be defined by the claims submitted herewith.

We claim:
 1. A method of repositioning an injection port, wherein theinjection port comprises a port body and a plurality of fasteners thatare integral with the port body, the method comprising: (a) positioningthe injection port at a first location in a patient's body; (b)extending the fasteners relative to the port body to substantiallysecure the injection port at the first location in the patient's body;(c) retracting the fasteners relative to the port body while theinjection port is at the first location in the patient's body, tosubstantially unsecure the injection port from the first location in thepatient's body; (d) moving the injection port to a second location inthe patient's body; (e) extending the fasteners relative to the portbody to substantially secure the injection port at the second locationin the patient's body; and (f) coupling the injection port with agastric band, wherein the injection port and the gastric band form aclosed fluid circuit.
 2. The method of claim 1, wherein the port body isreleasably engageable with a port applier, wherein the act ofpositioning the injection port is performed with the port body coupledwith the port applier.
 3. The method of claim 2, wherein the portapplier includes an actuator, wherein the act of extending the fastenersrelative to the port body to substantially secure the injection port atthe first location in the patient's body comprises actuating theactuator of the port applier.
 4. The method of claim 2, wherein the actsof moving the injection port to a second location in the patient's bodyand extending the fasteners relative to the port body to substantiallysecure the injection port at the second location in the patient's bodyare both performed with the port body coupled with the port applier. 5.The method of claim 2, further comprising releasing the port body fromthe port applier at the first location in the patient's body.
 6. Themethod of claim 5, wherein the acts of extending the fasteners relativeto the port body to substantially secure the injection port at the firstlocation in the patient's body and releasing the port body from the portapplier at the first location in the patient's body are both performedsubstantially simultaneously.
 7. A method of repositioning an injectionport, wherein the injection port comprises a port body and a pluralityof fasteners that are integral with the port body, the methodcomprising: (a) positioning the injection port adjacent tissue at afirst location in a patient's body; (b) extending the fasteners into thetissue at the first location to substantially secure the injection portat the first location in the patient's body; (c) retracting thefasteners from the tissue at the first location to substantiallyunsecure the injection port from the first location in the patient'sbody; (d) moving the injection port to a position adjacent tissue at asecond location in the patient's body; (e) extending the fasteners intothe tissue at the second location to substantially secure the injectionport at the second location in the patient's body; and (f) connectingthe port body to a gastric band thereby forming a closed fluid circuit.8. The method of claim 7, wherein the fasteners are selectivelyextendable relative to the port body.
 9. The method of claim 8, whereinthe act of extending the fasteners into the tissue at the first locationfurther comprises extending the fasteners relative to the port body. 10.The method of claim 7, wherein the fasteners are selectively retractablerelative to the port body.
 11. The method of claim 10, wherein the actof retracting the fasteners from the tissue at the first locationfurther comprises retracting the fasteners relative to the port body.12. The method of claim 7, wherein the act of extending the fastenersinto the tissue at the first location comprises pushing the fastenersinto the tissue at the first location; wherein the act of retracting thefasteners from the tissue at the first location comprises pulling thefasteners from the tissue at the first location; wherein the act ofextending the fasteners into the tissue at the second location comprisespushing the fasteners into the tissue at the second location.
 13. Themethod of claim 7, wherein the fasteners are rigid.
 14. The method ofclaim 7, wherein the fasteners are pivotally coupled with the port body.15. A method of repositioning an injection port, wherein the injectionport comprises a port body, a plurality of fasteners that are integralwith the port body, a septum that is integral with the port body, and anactuator that is integral with the port body, wherein the actuatorcomprises a ring defining an opening and an axis, wherein the septum isaligned along the axis, the method comprising: (a) positioning theinjection port adjacent tissue at a first location in a patient's body;(b) extending the fasteners into the tissue at the first location tosubstantially secure the injection port at the first location in thepatient's body, wherein the act of extending the fasteners into thetissue at the first location comprises moving the actuator in a firstdirection relative to the port body about the axis, wherein moving theactuator in the first direction comprises rotating the actuator in afirst rotational direction relative to the port body; (c) retracting thefasteners from the tissue at the first location to substantiallyunsecure the injection port from the first location in the patient'sbody, wherein the act of retracting the fasteners comprises moving theactuator in a second direction relative to the port body about the axis;(d) moving the injection port to a position adjacent tissue at a secondlocation in the patient's body; and (e) extending the fasteners into thetissue at the second location to substantially secure the injection portat the second location in the patient's body, wherein the act ofextending the fasteners into the tissue at the second location comprisesmoving the actuator in the first direction relative to the port body,wherein moving the actuator in the first direction comprises rotatingthe actuator in the first rotational direction relative to the portbody.
 16. The method of claim 15, wherein the act of moving the actuatorin the second direction relative to the port body comprises rotating theactuator in a second rotational direction relative to the port body.